SAN DIEGO – Nov. 29, 2018–Tocagen Inc. (Nasdaq: TOCA), a late clinical-stage, cancer-selective gene therapy company and NRG Oncology, a member of the National Cancer Institute’s (NCI) National Clinical Trial Network (NCTN), today announced that the NCI Cancer Therapy and Evaluation Program (CTEP) Brain Malignancies Steering Committee has approved a concept to develop a clinical trial utilizing the investigational therapeutic regimen Toca 511 (vocimagene amiretrorepvec) & Toca FC (flucytosine, extended-release) for the treatment of patients with newly diagnosed glioblastoma (GBM).

NRG Oncology, as one of the four adult group members of the NCI NCTN, conducts practice-defining, multi-institutional Phase 2 and 3 trials funded primarily by the NCI. The proposed Phase 2/3 trial (NRG-BN006) is expected to begin enrollment in 2019 and will be conducted by NRG Oncology under its NCI-funded grant, with Tocagen supplying investigational drug and supplemental financial support. Additional information about the trial will be provided in 2019.

Standard of care (SOC) for newly diagnosed GBM, the most common and deadly form of primary malignant brain tumor, involves surgical removal of as much of the tumor as possible followed by radiation therapy and temozolomide with use of tumor treating fields in a select group of patients. The proposed NRG-BN006 trial is designed to assess the benefit of adding Toca 511 & Toca FC to chemotherapy and radiation compared to SOC alone.

“The Brain Tumor Committee at NRG Oncology elected to conduct and sponsor the Toca 511 & Toca FC clinical trial in patients with newly diagnosed GBM based on the merits of published clinical data, which show extended overall survival compared to historical controls, durable complete responses and a favorable safety profile in patients with recurrent high grade glioma along with preclinical data that support a novel immune-activating mechanism of action, synergy with radiation therapy and additive efficacy in combination with temozolomide,” said Minesh P. Mehta, chair of the Brain Tumor Committee at NRG Oncology.

Added Manmeet Ahluwalia, Principal Investigator of the proposed study, “Glioblastoma remains a very high unmet need and there is excitement among the NRG Oncology membership to explore the potential of Toca 511 & Toca FC to enhance standard treatment to achieve greater tumor response and extend survival of patients with this aggressive type of cancer.”

Tocagen is currently studying Toca 511 & Toca FC for the treatment of recurrent high grade glioma (HGG) in the ongoing Phase 3 trial (Toca 5). Across three ascending-dose Phase 1 trials, Tocagen has treated 127 patients with recurrent HGG with Toca 511 & Toca FC. In these trials, Tocagen observed potential benefits, including ongoing durable complete responses, extended overall survival and a favorable safety profile. The proposed NRG-BN006 trial will be the first clinical trial of the Toca 511 & Toca FC regimen in the newly diagnosed GBM setting.

About NRG OncologyNRG Oncology conducts practice-changing, multi-institutional clinical and translational research to improve the lives of patients with cancer. Founded in 2012, NRG Oncology is a Pennsylvania-based nonprofit corporation that integrates the research of the NSABP Foundation, the Radiation Therapy Oncology Group (RTOG), and the Gynecologic Oncology Group (GOG). The research network seeks to carry out clinical trials with emphases on gender-specific malignancies, including gynecologic, breast and prostate cancers, and on localized or locally advanced cancers of all types. NRG Oncology’s extensive research organization comprises multidisciplinary investigators, including medical oncologists, radiation oncologists, surgeons, physicists, pathologists and statisticians, and encompasses more than 1,300 research sites located world-wide with predominance in the United States and Canada. NRG Oncology is supported primarily through grants from the National Cancer Institute (NCI) and is one of five research groups in the NCI’s National Clinical Trials Network.

About TocagenTocagen is a clinical-stage, cancer-selective gene therapy company developing first-in-class, broadly applicable product candidates designed to activate a patient's immune system against their own cancer. Tocagen's lead investigational product candidate, Toca 511 & Toca FC, is under evaluation in a pivotal Phase 3 trial (Toca 5) for recurrent high grade glioma (HGG), a disease with significant unmet medical need. The U.S. Food and Drug Administration awarded Tocagen an orphan drug grant for the Toca 5 trial and has granted Toca 511 & Toca FC Breakthrough Therapy Designation for the treatment of recurrent HGG. The European Medicines Agency has granted Toca 511 PRIME (PRIority MEdicines) designation for the treatment of glioma. For more information about Tocagen, visit www.tocagen.com.

Forward-Looking StatementsStatements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding our business plans and objectives, expectations regarding the initiation, timing and success of our planned clinical trials, expectations regarding Toca 511 & Toca FC’s ability to enhance the standard treatment for patients with newly diagnosed glioblastoma, and expectations regarding funding for the NRG-BN006 trial. Risks that contribute to the uncertain nature of the forward-looking statements include: the success, cost and timing of our product candidate development activities and planned clinical trials; our ability to execute on our strategy; regulatory developments in the United States and foreign countries; and our estimates regarding expenses, future revenue and capital requirements. These and other risks and uncertainties are described more fully under the caption "Risk Factors" and elsewhere in Tocagen's filings and reports with the United States Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made. Tocagen undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.